Re: [PATCH v3 2/2] dyndbg: use the module notifier callbacks
From: Vincenzo Palazzo
Date: Mon Mar 06 2023 - 12:59:11 EST
> Bring dynamic debug in line with other subsystems by using the module
> notifier callbacks. This results in a net decrease in core module
> code.
>
> Additionally, Jim Cromie has a new dynamic debug classmap feature,
> which requires that jump labels be initialized prior to dynamic debug.
> Specifically, the new feature toggles a jump label from the existing
> dynamic_debug_setup() function. However, this does not currently work
> properly, because jump labels are initialized via the
> 'module_notify_list' notifier chain, which is invoked after the
> current call to dynamic_debug_setup(). Thus, this patch ensures that
> jump labels are initialized prior to dynamic debug by setting the
> dynamic debug notifier priority to 0, while jump labels have the
> higher priority of 1.
>
> Tested by Jim using his new test case, and I've verfied the correct
> printing via: # modprobe test_dynamic_debug dyndbg.
>
> Link: https://lore.kernel.org/lkml/20230113193016.749791-21-jim.cromie@xxxxxxxxx/
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Link: https://lore.kernel.org/oe-kbuild-all/202302190427.9iIK2NfJ-lkp@xxxxxxxxx/
> Tested-by: Jim Cromie <jim.cromie@xxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> CC: Jim Cromie <jim.cromie@xxxxxxxxx>
> Cc: Luis Chamberlain <mcgrof@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Jason Baron <jbaron@xxxxxxxxxx>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@xxxxxxxxx>